Help needed on how to resolve a circular dependency.

[Dale Visser]

I'm attempting to modify AC_PROG_CC to include another macro that I'm
adding as well. The problem I'm hitting is that the new macro invokes
AC_COMPILE_IF_ELSE, which ends up doing an AC_REQUIRE([AC_PROG_CC}). Of
course, then autoconf is unhappy since AC_PROG_CC is effectively calling
AC_REQUIRE on itself.

The new macro is not specific to C. It can also be run for C++ and Fortran
projects, and I'm just focusing on making it work for C first. In fact, I
am attempting to integrate AX_FLAGS_WARN_ALL into autoconf (as per a
previous thread on this list in October:
https://lists.gnu.org/archive/html/autoconf/2013-10/msg00029.html). The
integration has been successful. This next part, making it used by default,
is what I'm attempting to do now.

In hindsight, it makes perfect sense that AX_FLAGS_WARN_ALL ends up
requiring AC_PROC_CC, because it produces test runs of the compiler to
check whether specific flags are supported by the current compiler.

Everything works just fine if my configure.ac just calls my new macro, but
what I really want to do is modify things such that by default AC_PROG_CC
invokes the new macro. Does anybody have advice, general or specific to my
case, about how best to untangle autoconf circular require dependencies?

Best regards,
Dale Visser

P.S. My apologies if any of this was unclearly or imprecisely stated. Macro
processing is something I rarely touch or have to worry, about unless you
count the occasional usage of Bourne shell variables in hand-written
scripts.

-- 
The plural of 'anecdote' is not 'data'.